1. Field of the Invention
The invention generally relates to a solar cell package and more particularly to a solar cell package including an improved double-sided solar cell mounted within a tubular transparent enclosure and having associated therewith a surface for redirecting incident rays to impinge on at least one side surface of the solar cell, whereby both sides of the solar cell is illuminated.
2. Description of the Prior Art
The prior art, of course, is replete with photovoltaic devices adapted to induce a current flow through an electrical circuit in response to incident solar radiation. While such devices are frequently employed in a celestial space environment the costs thereof attending usage in a terrestrial environment severely limits their utility. Substantial attention now is being given to the reduction of costs attending the use of photovoltaic devices, hereinafter referred to as solar cells, in a terrestrial environment so that the advantages thereof may be more fully appreciated.
Unlike most semiconductor devices, conventional solar cells have a significant value resulting solely from the material used in their fabrication, as opposed to the value added thereto as a consequence of fabrication. Consequently, cost reduction, and therefore increased usage of solar cells can be realized simply by reducing the quantity of silicon employed therein, once the processing steps for growing silicon cells are automated.
Currently, there are indications that single crystal silicon wafers cannot be fabricated and handled for minimum costs at thicknesses indicated suitable for adequate performance levels, such as four mills or less. Currently, the most practical thickness is in the range of for six-to-eight mills, or the thickness of two thin-type solar cells arranged in back-to-back contact. Therefore, in order to realize maximum cost effectiveness, fabrication and handling of solar cells having a thickness twice the thickness for adequate performance levels is desirable. However, from a cost effectiveness standpoint it is still necessary to make effective use of the total quantity of material included in the solar cells in order to realize cost savings.
Moreover, solar cells and similar devices usually are protected from the deleterious effects of terrestrial environments through use of glass sheets provided in an hermetically sealing relation therewith. The resulting device, while capable of withstanding the effects of wind, snow, rain, hail, blowing sand and the like, generally is considered to be impractical for many uses because of its cost in terms of time and material devoted to the fabrication thereof.
It generally is recognized that from a cost effectiveness standpoint it is cheaper to utilize a transparent or glass enclosure of a tubular configuration for encasing solar cells, since less material is used per unit area and glass tubes can be drawn as cheaply as being fabricated in any other structural form. However, one significant problem associated with the use of tubular enclosures or solar cells is that difficulty often is encountered in the rejection of excess heat from the solar cells.
In view of the foregoing, it should readily be apparent that there currently exists a need for a simplified solar cell package which is economic to fabricate and practical to employ in a terrestrial space environment.
It is therefore the general purpose of the instant invention to provide in a solar cell array for terrestrial use an economic and improved solar cell through which an increase in the usage of solar cells is realized in terrestrial environments.